Engineering anisotropic magnetoresistance of Hall bars with interfacial organic layers

Abstract

Tuning the magnetoresistance behavior of heterostructures composed of nonmagnetic and ferromagnetic (FM) materials is crucial for improving their applicability in electronic and spintronic devices. In this study, we investigate whether the integration of organic layers to NiFe/Pt junctions can result in the modification of the magnetic moment of the FM layer using iron phthalocyanines (FePc) and copper phthalocyanines (CuPc) as the interfacial layers for controlling the spin-charge conversion. Relaxation of the out-of-plane magnetic hard axis of the NiFe/Pt junctions is observed, as a result of the modification of the interfacial magnetic structure. The transport measurements of the fabricated hybrid Hall bar junctions with NiFe/FePc/Pt and NiFe/CuPc/Pt reveal that although the intrinsic anisotropic magnetoresistance of the present Hall bar is maintained with the integration of interfacial metal phthalocyanine (MPc) layers, a change in the magnetic response along the axis perpendicular to the in-plane of Hall bars is observed, owing to the insertion of the interfacial MPc layers. The present method of interface engineering via integration of organic interfacial layers can act as a model system for controlling the spin-charge conversion behavior of magnetic heterojunction toward the development of multifunctional molecular-engineered spintronic devices.